3.8 color scales

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<style>

/*Defining text stylings*/

#h1 {
  font-size:30px;
  margin:30px 0px 0px 20px;
  color:#f5fa91;
  font-family:'Montserrat Alternates', sans-serif;
  font-weight:300;
}

#link {
	font-family:'Montserrat Alternates', sans-serif;
  font-weight:200;
  font-size:10px;
	margin:5px 0px 0px 22px;
  color:white;
}

a:link, a:visited, a:active {
	text-decoration: none;
  color:white;
  border-bottom:1.5px dotted white;
}

body {
  background-color:#011227;
}

/*Defining button stylings*/

button {
  font-family:'Montserrat Alternates', sans-serif;
  font-weight:100;
  font-size:15px;
  margin:30px 0px 0px 50px;
  color:white;
  border:0;
  line-height:1.5;
  text-align:left;
  border-radius:1px;
  background-color:#011227;
}

button:hover {
  color:#f5fa91;
  background-color:#011227;
  font-weight:500;
}

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<body>
   

<p id="h1">COLOUR SCALE</p>
<div id="link">by
<a href="https://slides.com/sandravizmad">SANDRA</a></div>
  

<div class="Buttons"></div> 
  
<script>

//Margin conventions
var m = {top:20, right:20, bottom:20, left:40}
    w = 800 - m.left - m.right,
    h = 800 - m.top - m.bottom;

//Container
var svg = d3.select("body")
    .append("svg")
    .attr("width", w + m.left + m.right)
    .attr("height", h + m.top + m.bottom)
    .append("g")
		.attr("transform", `translate(${m.left}, ${m.top})`);

//Color scale
var c = d3.scaleLinear()
    .domain([0, w])
    .range(["#f5fa91", "#8ff798"]);

//Creating the bars
svg.selectAll(".bars")
    .data(d3.range(w), d => d)
    .enter()
    .append("rect")
    .attr("class", "bars")
    .attr("x", (d,i) => i)
    .attr("y", 0)
    .attr("height", 300)
    .attr("width", 2)
    .style("fill", (d,i) => c(d))

//Saving all scale names in a variable
var cscales = [
    "Cool",
    "Virdis",
    "Inferno",
    "Magma",
    "Plasma",
    "Warm",
    "Rainbow"
];

//Creating the buttons
d3.select(".Buttons")
    .selectAll("button")
    .data(cscales)
    .enter()
    .append("button")
    .text(d => d)
    .on("click", function(buttonValue) {

//New color scale
                  var cnew = d3.scaleSequential(d3["interpolate" + buttonValue])
                      .domain([0, w]);

//Animation to change to the new color scale
                  svg.selectAll(".bars")
                      .transition()
                      .duration(3000)
                      .style("fill",d => cnew(d));

});

</script>
</body>
</html>

https://d3js.org/d3.v4.min.js